The present inventio relates to an adjustable i.e. reencodible lock and key arrangement for doors, safe boxes or the like with two lock structures respectively associated with management and customer operation to operate independent from each other a common bolt.
In the case of rented safe deposit boxes it is customary to provide the door with two locks in order to make sure that two people are required for access to the box. This way an unauthorized use of one key or the other does not enable a particular person to gain access and e.g. burglarize the box. This then is a case of mutual dependency.
Furthermore it is customary in cases of safes or the like, particularly large bank vaults, walk-in safes to provide multiple locks for mutual monitoring and to prevent dishonest employees or bank robbers from gaining access to vaults, or to prevent hostage taking or the like. Multiple dependency for access requirements makes access more difficult. In all these instances multiple locks are to be operated requiring so to speak different independent sources before access is possible.
Aside from banks, other fields of use exist for safe deposit boxes, strong boxes or the like particularly in the private sphere such as hotels, offices or the like. In modern hotels the guest rooms and other rooms are individually accessible and through master keys; additional access is posible e.g. certain submaster keys gives access to all rooms in one floor. The general master key permits access to all rooms. Such a system is disadvantaged for the following reasons. If an individual key is lost the tumblers can be adjusted in a fairly simple fashion or exchanged. In the case of submaster keys or general master keys being lost or stolen, the situation is of course very different.
The new electronic locks no longer provide for access through a regular key but through encoded key cards. The encoding may be electrical or magnetical. These electronic keys can simply be reprogrammed or reencoded whenever there is a guest change. Such a key and lock combination requires electric current supply and other signal lines to run to the door which or course requires extensive stringing of cables and wires. The signal lines to be included should also provide for an indication as to the state of opening and closing of any and all doors. It is quite apparent that a hotel that is newly constructed may have cables installed in a comparatively simple fashion. The situation is quite different for refurbishing existing hotels. This is particularly so if under surface installation requires chiseling to open up the walls. Another disadvantage of course is the fact that electric or electronic lock and key arrangement of the type thus mentioned are more likely to be subject to interference as compared with purely mechanical locks. The maintenance problem is also increased.